1. Field of the Invention
The present invention relates generally to an electronic push-button type door locking device for an automotive vehicle, and more particularly to an electronic door locking system by which vehicle doors can be locked or unlocked when the driver depresses a plurality of push-button type switches in accordance with a predetermined code.
2. Description of the Prior Art
The background of the present invention is described with respect to its application with an automotive vehicle.
As is well-known, there exists an electronic push-button type door locking system for an automotive vehicle, by which vehicle doors can be locked or unlocked when the driver depresses a plurality of push-button type switches installed at an appropriate position on the outside of an automotive vehicle in accordance with a predetermined code. Use of such an electronic vehicle door locking system as described above to lock or unlock vehicle doors is very convenient for the driver since the vehicle doors can be locked or unlocked by the driver without using the ignition key. Such systems are particularly useful when the vehicle is left parked.
In the above-mentioned electronic door locking system, however, there exists the danger that the driver after having locked the doors by using the electronic push-button type door locking system, might carelessly forget that some of the vehicle devices or lights remain in operation and leave his vehicle. In this case, since the ignition key has already been extracted from the ignition keyhole, many devices or apparatus may be inoperative or remain turned off. However, since certain devices or lights can be operated or turned on or unlocked or opened even when the ignition key is not in the keyhole, in the case where the driver notices that a device is still in operation or kept turned on or unlocked dangerously or unsafely after having locked the doors, he must first unlock the doors, get in the car and depress a switch or turn off the devices or apparatus within the passenger compartment, thus necessitating a troublesome procedure.
The devices or lights described above are, for instance, a power-operated car-radio antenna, small lights (or dimmed headlights), a room light, a device for locking the trunk room or the console box, a device for closing the side door windows or the sunroof, etc.